Two-part or multi-part dental implant systems are well known in the field of dental implantology. Such systems generally comprise a dental implant which has an outer thread and which is designed to be anchored in the bone of the patient, and an abutment (also called a secondary part) which serves as a base for the prosthetic structure. The abutment is often fitted in a corresponding coronal opening of the dental implant, i.e. an opening directed toward the crown of the tooth in the implanted state.
A problem that often arises in multi-part dental implant systems of this kind concerns the correct positioning of the abutment in the dental implant. This problem has been considered in the following prior art documents, for example:
U.S. Pat. No. 5,281,140 discloses a two-part abutment. The latter comprises a first part, which at its lower end is designed to be fitted in a complementary opening of the dental implant, and which at its upper end has a projection with a multiplicity of side faces, in order to be received in a complementary opening of a second part of the abutment.
However, mainly because of the relatively large number of individual parts, the solution described in said document has disadvantages as regards the sterility and stability of the connection between the abutment and the dental implant.
Proceeding from this, EP-A-1728486 proposed an abutment for use in a dental implant system that has means for guiding and locking the abutment in the dental implant. Said means comprise an area with anti-rotation means. These anti-rotation means comprise a surface which extends radially with respect to the axis of the abutment and which is designed to cooperate with the dental implant in such a way that the abutment is guided during insertion into the dental implant.
Moreover, CA-A-2596988 describes an abutment which, in its apical area, has a groove which forms an indexing element for defining the rotation position with respect to the dental implant.
The solution described in EP-A-1728486 and the solution described in CA-A-2596988 are both directed to a conventional dental implant system on the basis of metals, e.g. titanium. However, in a connection according to said documents, the material of the dental implant system is subjected to relatively high stress, such that, particularly in dental implant systems that comprise a ceramic material, for example zirconium oxide, the problem is that the dental implant system may be damaged. This is especially the case when the forces acting on the dental implant system act obliquely with respect to the axis thereof.